DE69330059T2 - Soft eyepiece lens composition - Google Patents

Description

The present invention relates to an ocular lens material. More specifically, it relates to an ocular lens material with high oxygen permeability and high strength, which can be used for example for contact lenses, intraocular lenses or for artificial cornea. Hard contact lens material is known from EP-A 0 461 270.

It is already known that a soft material is usually preferred as a material for contact lenses because it is comfortable for its wearer to wear, or as a material for intraocular lenses, which in a modified form can be inserted through an incision on the eyeball without damaging eye tissue.

Such a soft material includes, for example, a water-absorptive material which swells and softens when it absorbs water, and a substantially non-water-absorptive material. In such a water-absorptive material, the oxygen permeability depends on the water absorptivity, and the oxygen permeability coefficient cannot be larger than the oxygen permeability coefficient of water. In recent years, as a material for contact lenses which are water-absorptive and have excellent oxygen permeability, a material composed of a copolymer of a fluorine-type (meth)acrylate monomer and a hydrophilic monomer such as acrylate has been proposed. B. 2-hydroxyethyl methacrylate, glycerol methacrylate or N,N-dimethylacrylamide, or a material made of a copolymer of such a hydrophilic monomer with a silicone type (meth)acrylate monomer (Japanese - Unexamined Patent Publication No. 179422/1991, No. 196117/1991 and No. 196118/1991).

However, in an attempt to increase the oxygen permeability of such a copolymer of a fluorine-type (meth)acrylate monomer with the hydrophilic monomer or a copolymer of a silicone-type (meth)acrylate monomer with the hydrophilic monomer, if the amount of the fluorine-type (meth)acrylate monomer is increased, for example, that of the silicone-type (meth)acrylate monomer, the resulting material is semi-hard.

Accordingly, it is difficult to obtain contact lenses that provide a comfortable feeling to their wearer or to obtain intraocular lenses that can be easily inserted through a small incision on the eyeball in a deformed state. In view of the above-mentioned state of the art, intensive studies have been carried out to obtain an ocular lens material that has the following properties: excellent transparency, excellent Oxygen permeability, adequate mechanical strength, relatively good rubber elasticity and excellent dimensional stability, suitable water absorbency (the water content is at least 5%) and softness in the water-containing state, low stickiness of the surface, low adhesion to dirt from e.g. lipids and easy processability by cutting and grinding. As a result, it was found that a copolymer comprising a certain specific polysiloxane macromonomer and an alkyl (meth)acrylamide as main components of the copolymer has such properties. The present invention has been accomplished based on this discovery. Thus, the present invention provides a soft ocular lens material having a water content of at least 5% by weight, which consists of a copolymer comprising as copolymerizable main components:

(A) a polysiloxane macromonomer having polymerizable groups bonded to the siloxane main chain via one or more urethane bonds, of formula (I)

A¹-U¹-S¹-U²-A² (I),

where A¹ is a group of formula (II)

Y²¹-R²¹-(II),

wherein Y²¹ is an acryloyloxy group, a methacryloyloxy group, a vinyl group or an allyl group and R³¹ is a linear or branched alkylene group having 2 to 6 carbon atoms,

A² is a group of formula (III)

- R³⁴-Y²² (III),

wherein Y²² is an acryloyloxy group, a methacryloyloxy group, a vinyl group or an allyl group and R³⁴ is a linear or branched alkylene group having 2 to 6 carbon atoms,

U1 is a group of formula (IV)

- X²¹-E²¹-X²⁵-R³²- (IV),

wherein X²¹ is a covalent bond, an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms, E²¹ is -CONH- (with the proviso that in this case X²¹ is a covalent bond and E²¹ forms a urethane bond with X²⁵) or a divalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic diisocyanates (with the proviso that in this case X²¹ is an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and E²¹ together with X²¹ and X²⁵ forms a urethane bond), X²⁵ an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and R³² is a linear or branched alkylene group having 1 to 6 carbon atoms, S¹ is a group of formula (V)

wherein R²³, R²⁴, R²⁵, R²⁵, R²⁷ and R²⁹ each independently represent an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group or a phenyl group, K is an integer from 1 to 50 and L is an integer from 0 to (50-K),

U² is a group of formula (VI)

- R³³-X²⁶-E²²-X²²- (V

wherein R³³ is a linear or branched alkylene group having 1 to 6 carbon atoms, X²² is a covalent bond, an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms, X²⁵ an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and E²² is -CONH- (with the proviso that in this case X²² is a covalent bond and E²² forms a urethane bond with X²⁵) or a divalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic diisocyanates (with the proviso that in this case X²² is an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and E²² forms a urethane bond together with X²² and X²⁵), and

(B) an alkyl(meth)acrylamide, wherein the weight ratio of the polysiloxane macromonomer (A) to the alkyl(meth)acrylamide (B) is 51/95 to 90/10. The present invention will now be described in detail with reference to preferred embodiments.

As described above, the ocular lens material of this invention is made of a copolymer comprising (A) a polysiloxane macromonomer of the formula (I) and (B) an alkyl(meth)acrylamide as main components, wherein the weight ratio of the polysiloxane macromonomer to the alkyl(meth)acrylamide is between 5/95 and 90/10. The above polysiloxane macromonomer has elastic bonds, urethane bonds, and is a component which in nature improves mechanical strength by the siloxane groups of the monomer without impairing the flexibility and oxygen permeability of the material and by imparting elasticity to prevent brittleness. Furthermore, the above polysiloxane macromonomer imparts high oxygen permeability because it has silicone chains in the molecule.

The above polysiloxane macromonomer has polymerizable groups at both ends of the molecule and can be copolymerized with other copolymerizable components through these polymerizable groups. Thus, it has the excellent property of imparting strength to the resulting ocular lens by chemical bonds (covalent bonds) in addition to the physical reinforcement effect by intertwining the molecules.

The above polysiloxane macromonomer is a compound of formula (I).

As mentioned above for formula (I), A¹ is a group of formula (II):

Y²¹-R³¹- (II)

where Y²¹ and R³¹ are as defined above, and A² is a group of formula (III):

- R³⁴-Y²² (III)

where Y²² and R³⁴ are as defined above.

Both Y²¹ and Y²² are polymerizable groups and are preferably acryloyloxy groups, methacryloyloxy groups or vinyl groups, making them easily copolymerizable with an alkyl(meth)acrylamide.

R³¹ and R³⁴ each represent a C₂₆ linear or branched alkylene group, preferably an ethylene group, a propylene group or a butylene group.

U¹ and U² are each groups containing a urethane bond in the molecular chain of the above polysiloxane macromonomer.

In U¹ and U², E²¹' and E²² each represent -CONH- as mentioned above or a bivalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic diisocyanates. Here, the bivalent group derived from a diisocyanate, wherein the diisocyanate is derived from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic diisocyanates, may be, for example, a bivalent group derived from a saturated aliphatic diisocyanate such as ethylene diisocyanate, 1,3- diisocyanatepropane or hexamethylene diisocyanate; a bivalent group derived from an alicyclic diisocyanate such as 1,2-diisocyanatecyclohexane, bis(4-isocyanatecyclohexyl)methane or isophorone diisocyanate; a bivalent group derived from an aromatic diisocyanate such as tolylene diisocyanate or 1, 5-diisocyanatonaphthalene; or a bivalent group derived from an unsaturated aliphatic diisocyanate such as 2,2'-diisocyanatodiethyl fumarate. Among these, a bivalent group derived from hexamethylene diisocyanate, a bivalent group derived from tolylene diisocyanate and a bivalent group derived from isophorone diisocyanate are preferred because they are comparatively readily available and are capable of imparting mechanical strength.

In U¹, X²¹ is a covalent bond when E²¹ is a -NHCO group, and E²¹ forms a urethane bond of the formula -OCO-NH- together with X²⁵. Furthermore, when E²¹ is the above-mentioned divalent group derived from a diisocyanate, X²¹ is an oxygen atom or a C₁₋₆ alkylene glycol group, and E²¹ forms a urethane bond together with X²¹ and X²⁵. X²⁵ is an oxygen atom or a C₁₋₆ alkylene glycol group, and R³² is a C₁₋₆ linear or branched alkylene group.

In U2, R33 is a C1-6 linear or branched alkylene group. X26 is an oxygen atom or a C1-6 alkylene glycol group. When E22 is a -CONH group, X22 is a covalent bond and E22 forms a urethane bond of the formula -OCO-NH- together with X26. Furthermore, when E22 is the above-mentioned divalent group derived from a diisocyanate, X22 is an oxygen atom or a C1-8 alkylene glycol group and E22 forms a urethane bond together with X22 and X26.

The C₁₋₆ alkylene glycol group of the above X²¹, X²⁵, X²² and X²⁶ may, for example, be a group of the formula (ViI):

- O-(CXH2x-O)y- (VII),

where x is an integer of 1 to 4 and y is an integer of 1 to 5. In formula (VII), the oxygen permeability tends to be low and the mechanical strength tends to deteriorate when y is an integer of 6 or more. Therefore, in the present invention, y is preferably an integer from 1 to 5, particularly preferably an integer from 1 to 3.

As mentioned above, S¹ is a group of formula (V).

In the formula (V), R²³, R²⁴, R²⁵, R²⁶, R²⁷ and R²⁹⁸ are, as mentioned above, independently a C₁₋₆ alkyl group, a fluoroalkyl group or a phenyl group.

Specific examples of the fluoroalkyl group include a 3,3,3-trifluoro-npropyl group, a 3,3,3-trifluoroisopropyl group, a 3,3,3-trifluoro-n-butyl group, a 3,3,3-trifluoroisobutyl group, a 3,3,3-trifluoro-sec-butyl group, a 3,3,3-trifluoro-tert-butyl group, a 3,3,3-trifluoro-n-pentyl group, a 3,3,3-trifluoroisopentyl group, a 3,3,3-trifluorothiopentyl group, and a 3,3,3-trifluorohexyl group. When a polysiloxane macromonomer having such a fluoroalkyl group is used for the present invention and the amount of such a polysiloxane macromonomer is increased, the resistance of the resulting ocular lens material to lipid contamination improves. K is an integer from 1 to 50, and L is an integer from 0 to (50 - K). When K + L is greater than 50, the molecular weight of the polysiloxane macromonomer becomes too large, and its compatibility with the alkyl (meth)acrylamide tends to become poor, causing it to fail to dissolve adequately when mixed and produce white turbidity when polymerized, and it becomes difficult to obtain a uniform transparent ocular lens material. When K + L = 0, the oxygen permeability of the resulting ocular lens material becomes low and the flexibility becomes poor. K + L is preferably an integer from 2 to 40, more preferably from 3 to 30.

The above-mentioned alkyl (meth)acrylamide is a component that imparts transparency and resistance to lipid fouling to the resulting ocular lens material, improves the water absorption capacity of the material, and facilitates cutting and grinding.

Such an alkyl (meth)acrylamide may be, for example, N,N-dimethyl (meth)acrylamide, N,N-dimethylaminopropyl methacrylamide or N-isopropyl (meth)acrylamide. These may be used alone or in combination as a mixture of two or more. Of these, N,N-dimethylacrylamide is preferred because it is possible to obtain a water-absorptive ocular lens material which has superior transparency and can be easily processed by cutting and grinding.

In this description, the term "(meth)acrylamide" stands for "acrylamide and/or methacrylamide".

The weight ratio of the above-mentioned polysiloxane macromonomer to the Alkyl (meth)acrylamide (i.e., polysiloxane macromonomer/alkyl (meth)acrylamide) is usually from 5/95 to 90/10, preferably from 10/90 to 90/10, more preferably from 10/90 to 80/20, and most preferably from 15/85 to 60/40. If the proportion of the polysiloxane macromonomer is smaller than the above ranges, the oxygen permeability of the resulting ocular lens material becomes inadequate, the mechanical strength or rubber elasticity becomes low, and the dimensional stability becomes poor. On the other hand, if the proportion of the polysiloxane macromonomer exceeds the above ranges, the proportion of the alkyl (meth)acrylamide decreases accordingly, whereby the resulting ocular lens material tends to become turbid, its surface becomes sticky, the resistance to lipid fouling becomes low, the water absorbency becomes low, and the treatment by cutting and grinding becomes difficult.

Furthermore, it is preferable that the total amount of the polysiloxane macromonomer and the alkyl (meth)acrylamide is at least 25% by weight, preferably at least 30% by weight, more preferably at least 35% by weight, based on the total amount of copolymerizable components. If this total amount is less than 25% by weight, the resulting ocular lens material tends to be difficult to process by cutting and grinding and to be sticky.

In this invention, a silicone-containing monomer selected from the group consisting of a silicone-containing alkyl (meth)acrylate and a silicone-containing styrene derivative can be used as another copolymerizable component to further increase the oxygen permeability and improve the mechanical strength.

Such a silicone-containing alkyl (meth)acrylate can be, for example, one of the following:

Trimethylsiloxydimethylsilylmethyl(meth)acrylate, Trimethylsiloxydimethylsilylpropyl(meth)acrylate, Methylbis(trimethylsiloxy)silylpropyl(meth)acrylate, Tris(trimethylsiloxy)silylpropyl(meth)acrylate, Mono[methylbis(trimethylsiloxy)siloxy]bis(trimethylsiloxy)silylpropyl(meth)acrylate, Tris[methylbis(trimethylsiloxy)siloxy]silylpropyl(meth)acrylate, Methylbis(trimethylsiloxy)silylpropylglyceryl(meth)acrylate, Tris(trimethylsiloxy)silylpropylglyceryl(meth)acrylate, Mono[methylbis(trimethylsiloxy)siloxy]bis(trimethylsiloxy)silylpropylglyceryl(meth) acrylate, trimethylsilylethyltetramethyldisiloxypropylglyceryl (meth)acrylate, trimethylsilylmethyl (meth)acrylate, trimethylsilylpropyl (meth)acrylate, Trimethylsilylpropylglyceryl (meth)acrylate, trimethylsiloxydimethylsilylpropylglyceryl (meth)acrylate, methylbis(trimethylsiloxy)silylethyltetramethyldisiloxymethyl (meth)acrylate, Tetramethyltriisopropylcyclotetrasiloxanylpropyl (meth)acrylate or tetramethyltriisopropylcyclotetrasiloxybis(trimethylsiloxy)silylpropyl (meth)acrylate. In this description, "(meth)acrylate" means "acrylate and/or methacrylate", and the same applies to other (meth)acrylate derivatives.

The above-mentioned silicone-containing styrene derivative can be, for example, a compound of formula (VIII):

wherein p is an integer of 1 to 15, q is 0 or 1, and r is an integer of 1 to 15. In the silicone-containing styrene derivative of the formula (VIII), when p or r is an integer of 16 or more, the synthesis and purification of such a derivative becomes difficult and the hardness of the resulting ocular lens material tends to be low, and when q is an integer of 2 or less, the production of such an organopolysiloxane-containing styrene derivative becomes difficult.

Typical examples of the compound of formula (VIII) include:

Tris(trimethylsiloxy)silylstyrene, Bis(trimethylsiloxy)methylsilylstyrene, (Trimethylsiloxy)dimethylsilylstyrene, Tris(trimethylsiloxy)siloxydimethylsilylstyrene, [Bis(trimethylsiloxy)methylsiloxy]dimethylsilylstyrene, (Trimethylsiloxy)dimethylsilylstyrene, Heptamethyltrisiloxanylstyrene, Nonamethyltetrasiloxanylstyrene, Pent adecamethylheptasiloxanylstyrene, heneicosamethyldecasiloxanylstyrene, heptacosamethyltridecasiloxanylstyrene, hentriacontamethylpentadecasiloxanylstyrene, trimethylsiloxypentamethyldisoloxymethylsilylstyrene , tris(pentamethyldisiloxy)silylstyrene, tris(trimethylsiloxy)siloxybis(trimethylsiloxy)silylstyrene, Bis(heptamethyltrisiloxy)methylsilylstyrene, tris[methylbis(trimethylsiloxy)siloxy]silylstyrene, trimethylsiloxybis[tris(trimethylsiloxy)siloxy]silylstyrene, heptakis(trimethylsiloxy)trisiloxanylstyrene, nonamethyltetrasiloxyundecylmethylpentasiloxymethylsilylstyrene, tris[tris(trimethylsiloxy)siloxy]silylstyrene, (Tri strimethylsiloxyhexamethyl)-tetrasiloxy[ tris(trimethylsiloxy)siloxy]trimethylsiloxysilylstyrene, nonakis(trimethylsiloxy)tetrasiloxanylstyrene, bis(tridecamethylhexasiloxy)methylsilylstyrene, Heptamethylcyclotetrasiloxanylstyrene, heptamethylcyclotetrasiloxybis(trimethylsiloxy)silylstyrene, tripropyltetramethylcyclotetrasiloxanylstyrene and trimethylsilylstyrene.

These silicone-containing monomers may be used alone or in combination as a mixture of two or more. Of these silicone-containing monomers, a silicone-containing alkyl (meth)acrylate such as tris(trimethylsiloxy)silylpropyl (meth)acrylate is preferably used because it is possible to obtain an ocular lens material having good mechanical strength without reducing oxygen permeability. Further, a silicone-containing styrene derivative such as tris(trimethylsiloxy)silylstyrene is used because it is possible to obtain an ocular lens material having excellent transparency and good mechanical strength in a wide range of proportions and having a relatively high refractive index. This high refractive index makes it possible to produce a thin ocular lens of the same power, whereby oxygen permeability is excellent due to the small thickness of the contact lens.

It is advisable to set the content of such a silicone-containing monomer to not more than 75% by weight, preferably not more than 70% by weight, more preferably not more than 65% by weight of the total amount of copolymerizable components. If the content of such a silicone-containing monomer exceeds 75% by weight, the total amounts of the polysiloxane macromonomer and the alkyl (meth)acrylamide become relatively small, making it difficult to obtain the desired ocular lens material of this invention. On the other hand, such a silicone-containing monomer is used at least 10% in order to adequately obtain the effect of such a silicone-containing monomer.

In this invention, the copolymer is obtained by using the polysiloxane macromonomer and the alkyl (meth)acrylamide as main components, and, as required, the siloxane monomer is used as another copolymerizable component. A monomer having an unsaturated double bond which is copolymerizable with such copolymerizable components can be used as another copolymer component. Such another copolymer component can be used to impart hardness or softness and resistance to lipid staining to the resulting ocular lens material, to adjust the water absorbency of the material, to impart improved stability and durability by crosslinking, to impart ultraviolet absorbency, or for coloring.

For example, to impart hardness (or softness or flexibility by adjusting the degree of hardness), one or more compounds from the following group can be selected: linear, branched or cyclic alkyl (meth)acrylates, Alkoxyalkyl (meth)acrylates and alkylthioalkyl (meth)acrylates such as. B. Methyl (meth)acrylate, ethyl (meth)acrylate, ispropyl (meth)acrylate, n-propyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, t-butyl (meth)acrylate , pentyl (meth)acrylate, t-pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, nonyl (meth)acrylate, stearyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, meth)acrylate, Ethylthioethyl (meth)acrylate and methylthioethyl (meth)acrylate; styrene; α-methylstyrene; alkylstyrenes such as methylstyrene, ethylstyrene, propylstyrene, butylstyrene, t-butylstyrene, isobutylstyrene and pentylstyrene; and alkyl-α-methylstyrenes such as methyl-α-methylstyrene, ethyl-α-methylstyrene, propyl-α-methylstyrene, butyl-α-methylstyrene, t-butyl-α-methylstyrene, isobutyl-α-methylstyrene and pentyl-α-methylstyrene. The content of such an additional copolymer component is usually not more than 60% by weight, preferably not more than 50% by weight, more preferably not more than 40% by weight of the total amount of the copolymerizable components. If this content exceeds 60 wt%, the content of the above polysiloxane macromonomer becomes relatively small, whereby the oxygen permeability and mechanical strength become low. Furthermore, the following compounds can be used alone or as a mixture of two or more to adjust the water absorbency of the resulting ocular lens material: hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate and hydroxypropyl (meth)acrylate; (alkyl)aminoalkyl (meth)acrylates such as 2-dimethylaminoethyl (meth)acrylate and 2-butylaminoethyl (meth)acrylate; polyglycol mono(meth)acrylates such as propylene glycol mono(meth)acrylate; vinylpyrrolidone; (meth)acrylic acid; maleic anhydride; fumaric acid; fumaric acid derivatives; aminostyrene and hydroxystyrene. The content of such an additional copolymerizable component is usually not more than 50% by weight, preferably not more than 30% by weight, more preferably not more than 20% by weight based on the total amount of copolymerizable components. If this content exceeds 50% by weight, the content of the polysiloxane macromonomer becomes relatively small, so that high oxygen permeability and high mechanical strength can hardly be expected. In order to impart lipid fouling repellency to the resulting ocular lens material, for example, a fluorine-containing monomer of the formula (IX) can be used:

CH 2 =CR 4 COOCSH(2st+1) Ft (IX)

wherein R4 is hydrogen or methyl, s is an integer from 1 to 15, and t is an integer from 1 to (25+1).

Specific examples of the monomer of formula (IX) above include:

2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 2,2,3,3-tetrafluoro-t-pentyl (meth)acrylate, 2, 2,3, 4,4,4-Hexafluorobutyl (meth)acrylate, 2,2,3,4,4,4-hexafluoro-t-hexyl (meth)acrylate, 2,3,4,5,5,5-hexafluoro-2, 4-bis(trifluoromethyl)pentyl(meth)acrylate, 2,2,3,3,4,4-hexafluorobutyl(meth)acrylate, 2, 2,2,2',2',2'-hexafluoroisopropyl(meth)acrylate , 2, 2,3,3,4,4,4-heptafluorobutyl (meth)acrylate, 2, 2,3, 3,4,4,5,5-Octafluoropentyl (meth)acrylate, 2,2,3,3,4,4,5,5,5-Nonafluoropentyl (meth)acrylate, 2,2,3,3,4, 4,5,5,6,6,7,7-dodecafluoroheptyl (meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8,8-dodecafluorooctyl (meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl (meth)acrylate, 2,2,3,3,4,4,5,5,6, 6,7,7,7-Tridecafluoroheptyl (meth)acrylate, 3,3,4,4,5, 5,6,6,7,7,8,8,9,9,10,10-hexadecafluorodecyl (meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8, 8,9,9,10,10,10-Heptadecafluorodecyl(meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10, 11,11-Octadecafluorundecyl(meth)acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9, 10,10,11,11,11-Nonadecafluorundecyl( meth)acrylate and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12-eicosafluorododecyl (meth)acrylate.

The content of the above fluorine-containing monomer is usually not more than 40% by weight, preferably not more than 30% by weight, more preferably not more than 20% by weight based on the total amount of copolymerizable components. If this content exceeds 40% by weight, the content of the polysiloxane macromonomer becomes relatively small, whereby high oxygen permeability and high mechanical strength can hardly be expected.

To further impart improved mechanical strength and durability to the resulting ocular lens material, a further copolymerizable addable component may be, for example, one of the following crosslinking agents:

Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, trimethylolpropane tri(meth)acrylate, methacryloxyloxyethyl acrylate, Divinylbenzene, diallyl phthalate, diallyl adipate, triallyl isocyanurate, α-methylene-N-vinylpyrrolidone, 4-vinylbenzyl (meth)acrylate, 3-vinylbenzyl (meth)acrylate,

2,2-Bis(p-(meth)acryloyloxyphenyl)hexafluoropropane,

2,2-Bis(m-(meth)acryloyloxyphenyl)hexafluoropropane,

2,2-Bis(o-(meth)acryloyloxyphenyl)hexafluoropropane,

2,2-bis(p-(meth)acryloyloxyphenyl)propane, 2,2-bis(m-(meth)acryloyloxyphenyl)propane, 2,2-bis(o-(meth)acryloyloxyphenyl)propane,

1,4-(Bis(2-(meth)acryloyloxyhexafluoroisopropyl)benzene,

1, 3-Bis(2-(meth)acryloyloxyhexafluoroisopropyl)benzene,

1,2-Bis(2-(meth)acryloyloxyhexafluoroisopropyl)benzene,

1,4-Bis(2-(meth)acryloyloxyisopropyl)benzene, 1,3-Bis(2-(meth)acryloyloxyisopropyl)benzene, 1,2-Bis(2-(meth)acryloyloxyisopropyl)benzene.

These crosslinking agents may be used alone or in combination as a mixture of two or more. The content of such a crosslinking agent is usually from 0.01 to 10 parts by weight, preferably from 0.05 to 8 parts by weight, more preferably from 0.1 to 5 parts by weight, per 100 parts by weight of the total amount of copolymerizable components. If the content of the crosslinking agent is less than 0.01 part by weight, adequate effects are not usually obtained by using such a crosslinking agent. On the other hand, if the content exceeds 10 parts by weight, the material tends to become brittle.

In order to further impart ultraviolet absorbency or color to the ocular lens material, for example, a copolymerizable ultraviolet absorber, a polymerizable dye or a polymerizable ultraviolet absorbing dye can be used as another copolymerizable component.

Specific examples of the polymerizable ultraviolet absorber include: benzophenone-type polymerizable ultraviolet absorbers such as 2-hydroxy-4-(meth)acryloyloxybenzophenone,

2-Hydroxy-4-(meth)acryloyloxy-5-tert-butylbenzophenone,

2-Hydroxy-4-(meth)acryloyloxy-2',4'-dichlorobenzophenone and

2-Hydroxy-4-(2'-hydroxy-3'-(meth)acryloyloxypropoxy)benzophenone;

polymerizable ultraviolet absorbers of the benzotriazole type, such as

2-(2'-Hydroxy-5'-(meth)acryloyloxyethylphenyl)-2H-benzotriazole,

2-(2'-Hydroxy-5'-(meth)acryloyloxypropylphenyl)-2H-benzotriazole and

2-(2'-Hydroxy-5'-(meth)acryloyloxyethylphenyl)-5-chloro-2H-benzotriazole and 2-(2'-Hydroxy-5'-(meth)acryloyloxypropyl)-3'-tert-butylphenyl)- 5-chloro-2H-benzotriazole;

polymerizable ultraviolet absorbers of the salicylic acid derivative type such as phenyl-2-hydroxy-4-(meth)acryloyloxymethylbenzoate; and other polymerizable ultraviolet Absorbers such as methyl 2-cyano-3-phenyl-3-(3'-(meth)acryloyloxyphenyl)propenoate. These polymerizable ultraviolet absorbers can be used alone or in combination as a mixture of two or more.

Specific examples of the polymerizable dye include:

polymerizable azo dyes such as

1-Phenylazo-4-(meth)acryloyloxynaphthalene,

1-Phenylazo-2-hydroxy-3-(meth)acryloyloxynaphthalene,

1-Naphthylazo-2-hydroxy-3-(meth)acryloyloxynaphthalene,

1-(α-Anthrylazo)-2-hydroxy-3-(meth)acryloyloxynaphthalene,

1-((4'-Phenylazo)phenyl)azo)-2-hydroxy-3-(meth)acryloyloxynaphthalene,

1-(2',4'-Xylylazo)-2-(meth)acryloyloxynaphthalene, 1-(o-tolylazo-2-(meth)acryloyloxynaphthalene,

2-(m-(meth)acryloylamidanilino)-4,6-bis(1'-(o-tolylazo)-2'-naphthylamino)-1,3,5-triazine,

2-(m-vinylanilino)-4-((4'-nitrophenylazo)anilino)-6-chloro-1,3,5-triazine,

2-(1'-(o-Tolylazo)-2'-naphthyloxy-4-(m-vinylanilino)-6-chloro-1,3,5-triazine,

2-(p-vinylanilino)-4-(1'-(o-tolylazo)-2'-naphthylamino)-6-chloro-1,3,5-triazine,

N-(1'-(o-Tolylazo)-2'-naphthyl)-3-vinylphthalic acid monoamide,

N-(1'-(o-Tolylazo)-2'-naphthyl)-6-vinylphthalic acid monoamide,

3-vinylphthalic acid (4'-(p-sulfophenylazo)-1'-naphthyl) monoester,

6-vinylphthalic acid (4'-(p-sulfophenylazo)-1'-naphthyl) monoester,

3-(Meth)acryloylamide-4-phenylazophenol,

3-(Meth)acryloylamide-4-(8'-hydroxy-3',6'-disulfo-1'-naphthylazo)phenyl,

3-(Meth)acryloylamide-4-(1'-phenylazo-2'-naphthylazo)phenol,

3-(Meth)acryloylamide-4-(p-tolylazo)phenol,

2-Amino-4-(m-(2'=hydroxy-1'-naphthylazo)anilino)-6-isopropenyl-1,3,5-triazine,

2-Amino-4-(N-methyl-p-(2'-hydroxy-1'-naphthylazo)anilino)-6-isopropenyl-1,3,5-triazine,

2-Amino-4-(m-(4'-hydroxy-1'-phenylazo)anilino)-6-isopropenyl-1,3, 5-triazine,

2-Amino-4-(N-methyl-p-(4'-hydroxyphenylazo)anilino)-6-isopropenyl-1,3,5-triazine,

2-Amino-4-(m-(3'-methyl-1'-phenyl-5'-hydroxy-4'-pyrazolylazo)anilino)-6-isopropenyl-1,3,5-triazine, 2-amino-4 -(N-methyl-p-(3'-methyl-1'-phenyl-5'-hydroxy-4'-pyrazolylazo)anilino)-6-isopropenyl-1,3, 5-triazine, 2-amino-4- (p-phenylazoanilino)-6-isopropenyl-1,3,5-triazine and 4-phenylazo-7-(meth)acryloylamide-1-naphthol;

polymerizable anthraquinone dyes such as 1,5-bis((meth)acryloylamino)-9,10-anthraquinone, 1-(4'-vinylbenzoylamide)-9,10-anthraquinone,

4-Amino-1-(4'-vinylbenzoylamide)-9, 10-anthraquinone, 5-amino-1-(4'-vinylbenzoylamide)-9, 10-anthraquinone, 8-amino-1-(4'-vinylbenzoylamide) -9,10-anthraquinone, 4-nitro-1-(4'-vinylbenzoylamide)-9,10-anthraquinone, 4-hydroxy-1-(4'-vinylbenzoylamide)-9,10-anthraquinone, 1-(3' -vinylbenzoylamide)-9,10-anthraquinone, 1-(2'-vinylbenzoylamide)-9,10-anthraquinone, 1-(4'-isopropenylbenzoylamide)-9,10-anthraquinone, 1-(3'-isopropenylbenzoylamide)-9, 10-anthraquinone, 1-(2'-isopropenylbenzoylamide)-9, 10-anthraquinone, 1,4-bis-(4'-vinylbenzoylamide)-9,10-anthraquinone, 1 ,4-Bis-(4'-isopropenylbenzoylamide)-9,10-anthraquinone, 1,5-bis-(4'-vinylbenzoylamide)-9,10-anthraquinone, 1,5-bis-(4'-isopropenylbenzoylamide)- 9, 10- anthraquinone, 1-Methylamino-4-(3'-vinylbenzoylamide)-9,10-anthraquinone, 1-methylamino-4-(4'-vinylbenzoyloxyethylamino)-9,10-anthraquinone, 1-amino-4-(3'-vinylphenylamino) -9, 10-anthraquinone-2-sulfonic acid, 1-amino-4-(4'-vinylphenylamino)-9,10-anthraquinone-2-sulfonic acid, 1-amino-4-(2'-vinylbenzylamino)-9,10-anthraquinone- 2-sulfonic acid, 1-amino-4-(3'-(meth)acryloylaminophenylamino)-9,10-anthraquinone-2-sulfonic acid, 1-amino-4-(3'-(meth)acryloylaminobenzylamino)-9,10- anthraquinone-2-sulfonic acid, 1-(β-ethoxycarbonylallylamino)-9,10-anthraquinone, 1-(β-carboxyallylamino)-9,10-anthraquinone, 1,5-di-(β-carboxyallylamino)-9,10-anthraquinone, 1-(β-isopropoxycarbonylallylamino)-5-benzoylamide-9,10 -anthraquinone, 2-(3'-(meth)acryloylamidanilino)-4-(3'-(3"-sulfo-4"-aminoanthraquinone-1"-yl)aminoanilino)-6-chloro-1,3,5- triazine, 2-(3'-(meth)acryloylamidanilino)-4-(3'-(3"-sulfo-4"-aminoanthraquinon-1"-yl)aminoanilino)-6-hydrazino-1,3,5-triazine ,

2,4-Bis-((4"-Methoxyanthraquinone-1"-yl)amino)-6-(3'-vinylanilino)-1, 3, 5-triazine and 2-(2'-Vinylphenoxy)-4-( 4'-(3"-sulfo-4"-aminoanthraquinone-1"-yl-amino)anilino)-6-chloro-1,3,5-triazine;

nitro-type polymerizable dyes such as o-nitroanilinomethyl (meth)acrylate and polymerizable phthalocyanine dyes such as (meth)acryloyl-modified tetraamino-copper phthalocyanine and (meth)acryloyl-modified (dodecanoyl-modified tetraamino-copper phthalocyanine). These polymerizable dyes can be used alone or in combination as a mixture of two or more.

Specific examples of the polymerizable ultraviolet absorbing dye include benzophenone-type polymerizable ultraviolet absorbing dyes such as:

2,4-Dihydroxy-3-(p-styrenoazo)benzophenone,

2,4-Dihydroxy-5-(p-styrenoazo)benzophenone,

2,4-Dihydroxy-3-(p-(meth)acryloyimethylphenylazo)benzophenone,

2,4-Dihydroxy-5-(p-(meth)acryloyloxymethylphenylazo)benzophenone,

2,4-Dihydroxy-3-(p-(meth)acryloyloxyethylphenylazo)benzophenone,

2,4-Dihydroxy-5-(p-(meth)acryloyloxyethylphenylazo)benzophenone,

2,4-Dihydroxy-3-(p-(meth)acryloyloxypropylphenylazo)benzophenone,

2,4-Dihydroxy-5-(p-(meth)acryloyloxypropylphenylfazo)benzophenone,

2,4-Dihydroxy-3-(o-(meth)acryloyloxymethylphenylazo)benzophenone,

2,4-Dihydroxy-5-(o-(meth)acryloyloxymethylphenylazo)benzophenone,

2,4-Dihydroxy-3-(o-(meth)acryloyloxyethylphenylazo)benzophenone,

2,4-Dihydroxy-5-(o-(meth)acryloyloxyethylphenylazo)benzophenone,

2,4-Dihydroxy-3-(o-(meth)acryloyloxypropylphenylazo)benzophenone,

2,4-Dihydroxy-5-(o-(meth)acryloyloxypropylphenylazo)benzophenone,

2,4-Dihydroxy-3-(p-(N,N-di(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-5-(p-(N,N-di(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-3-(o-(N, N-di(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-5-(o-(N, N-di(meth)acryloylethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-3-(p-(N-ethyl-N-(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-5-(p-(N-ethyl-N-(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-3-(o-(N-ethyl-N-(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-5-(o-(N-ethyl-N-(meth)acryloyloxyethylamino)phenylazo)benzophenone,

2,4-Dihydroxy-3-(p-(N-ethyl-N-(meth)acryloylamino)phenylazo)benzophenone,

2,4-Dihydroxy-5-(p-(N-ethyl-N-(meth)acryloylamino)phenylazo)benzophenone,

2,4-Dihydroxy-3-(o-(N-ethyl-N-(meth)acryloylamino)phenylazo)benzophenone and

2,4-Dihydroxy-5-(o-(N-ethyl-N-(meth)acryloylamino)phenylazo)benzophenone and

benzoic acid type polymerizable ultraviolet absorbing dyes such as 2-hydroxy-4- (p-styrenoazo)benzoic acid phenyl ester. These polymerizable ultraviolet absorbing dyes can be used alone or in combination as a mixture of two or more.

The amounts of the above-mentioned polymerizable ultraviolet absorber, polymerizable dye and polymerizable ultraviolet absorbing dye are essentially determined by the thickness of the lens, and are preferably not more than 3 parts by weight, more preferably 0.1 to 2 parts by weight, per 100 parts by weight of the Total amount of polymerized monomers. If the content exceeds 3 parts by weight, the physical properties of the lens such as mechanical strength will deteriorate. Because of the toxicity of the ultraviolet absorber or dye, these materials are generally not used as materials for ocular lenses, such as contact lenses that are in direct contact with living tissue or intraocular lenses that are embedded in the body. If the content becomes too large, especially in the case of dyes, the color of the lens may become so intense that the transparency decreases and visible light hardly penetrates the lens.

Depending on the particular purpose of the desired ocular lens (contact lens or intraocular lens), the polysiloxane macromonomer and the alkyl (meth)acrylamide, as well as the siloxane monomer and the additional copolymerizable components, are suitably adjusted and subjected to copolymerization. In this invention, the polysiloxane monomer and the alkyl (meth)acrylamide, as well as the siloxane monomer and the additional copolymerizable components, used as the case may be, are adjusted to be present in the desired ratio within the above-mentioned ranges, and a radical polymerization initiator is added, followed by polymerization according to known methods.

This known method may be one of the following: slowly heating the mixture after the addition of the radical polymerization initiator to a temperature between room temperature and about 120°C, irradiation with electromagnetic waves such as microwaves, ultraviolet radiation or gamma radiation. In the case of polymerization by heat, the temperature may be gradually increased. The polymerization may be carried out by block polymerization or by polymerization in solution, e.g. using a solvent, or in any other way.

Specific examples of the radical polymerization initiator include azobisisobutylnitrile, azobisdimethylvaleronitrile, benzoyl peroxide, tert-butyl hydroperoxide and cumyl hydroperoxide. These radical polymerization initiators may be used alone or in combination as a mixture of two or more. In the case of photopolymerization, a photopolymerization initiator or sensitizer is preferably added. The above photopolymerization initiators or sensitizers are usually used in an amount of about 0.001 to 2 parts by weight, preferably 0.01 to 1 part by weight per 100 parts by weight of the total amount of copolymerizable components.

Methods generally known to the person skilled in the art can be used to form ocular lenses such as contact lenses or intraocular lenses. Such methods can include, for example: are called turning and grinding and casting. In the cutting and grinding method, polymerization is carried out in a suitable mold or vessel to obtain a rod, block or plate-shaped base material (polymer). Then, the base material is formed into a desired shape by mechanical processing such as cutting, grinding and smoothing. In the casting method, a mold corresponding to that of the desired ocular lens is prepared and polymerization of the above lens components is carried out in this mold to obtain a casting which can be subjected to further mechanical finishing if necessary.

Besides the above methods, it is also possible to apply to this invention a method in which a monomer capable of forming a hard polymer is impregnated into a lens material. Then, the monomer is polymerized to harden the whole, which is then subjected to cutting and grinding treatment. From a product formed into a desired shape, the hard polymer is removed to obtain a molded product of the lens material (Japanese Unexamined Patent Publication No. 278024/1987 and No. 11854/1989).

Furthermore, a lens holding piece may be manufactured separately from the lens and then bonded thereto, or it may be molded together with the lens. Now, the ocular lens material of this invention will be described in detail by means of examples, but this invention is not limited to these examples.

EXAMPLE 1

20 parts by weight of a polysiloxane macromonomer containing a urethane bond having the following formula:

(hereinafter referred to as macromonomer A), 80 parts by weight of N,N-dimethylacrylamide, 0.5 part by weight of ethylene glycol dimethacrylate and 0.1 part by weight of 2,2'-azobis(2,4- dimethylvaleronitrile) as a polymerization initiator were uniformly mixed to obtain a transparent solution. This solution was filled into a glass test tube. Then, such a test tube was placed in a constant temperature circulating bath and heated at 35°C for 40 hours and at 50°C for 8 hours. Thereafter, it was placed in a drying oven with circulating air, and polymerization was carried out by gradually raising the temperature to 110°C (10°C per 2 hours) to obtain a rod-shaped copolymer having a diameter of 13.5 mm. The obtained rod-shaped copolymer was subjected to hydration treatment and then cut into pieces with a thickness of 0.2 mm, which were then subjected to grinding and polishing treatment to obtain test pieces. Various physical properties of the test pieces were measured according to the following methods. The results are shown in Table 1.

(a) Transparency

A test specimen in water was visually inspected and evaluated according to the following standards.

Assessment standards

O: transparent

Δ: slightly cloudy

X: very cloudy

(b) Flexibility

A test specimen was pulled on both sides and the extensibility was examined and evaluated according to the following evaluation standards.

Assessment standards

O: very stretchy

Δ: not very stretchy

X: hardly stretchable

(c) Stickiness

A test piece was touched with a finger and the detachability from the test piece was examined and evaluated according to the following evaluation standards.

Assessment standards

O: the finger comes off easily

Δ: the finger is a little harder to release

X: the finger is difficult to release

(d) Penetration force

Using an indentation force tester, a pressure needle with a diameter of 1.59 mm (1/16 inch) was pressed against the center of a test specimen and the compression force at fracture of the test specimen was measured. The values listed in Table 1 are values calculated for a test specimen thickness of 0.2 mm.

(e) Expansion

The elongation (%) at the time of fracture of the test specimen in the above-mentioned measurement of penetration strength (g) was measured.

(f) Oxygen permeability coefficient (DK0.2)

The oxygen permeability coefficient of a test specimen was measured in a physiological saline solution at 35ºC with a Seikaken type oxygen permeability measuring instrument manufactured by Rika Seiki Kogyo Kabushiki Kaisha. The unit of the oxygen permeability coefficient is ml(STP)·cm²/(cm³·s·mmHg). The oxygen permeability coefficients in Table 1 are numerical values obtained by multiplying the values of the oxygen permeability coefficients by the thickness of the test specimens, which is 0.2 mm x 10".

(g) Water content

A test specimen was subjected to hydration treatment and then the water content in wt% of the test specimens was determined according to the following formula:

where W is the weight (g) of a test specimen after absorption of water to equilibrium after hydration treatment and Wo is the weight (g) of the above-mentioned test specimen, which was dried in a dryer until dry after the hydration treatment.

(h) Refractive index

The refractive index was measured at a temperature of 25ºC at a relative humidity of 50% using an Atago refractometer IT manufactured by Kabushiki Kaisha Atago.

(i) Resistance to lipid fouling (test for deposition of lauric acid on the surface)

0.2 g of lauric acid (CH3(CH2)10COOH) and 100 ml of distilled water were charged into a 100 ml Erlenmeyer flask and stirred at about 50°C to obtain a dispersion of lauric acid. Then, a hydrated test piece was put into the dispersion and stirred for 10 minutes. The test piece was taken out and gently rinsed with distilled water of about 50°C. Then, it was allowed to dry. Then, the deposition degree of lauric acid was visually observed and evaluated according to the following evaluation standards.

Assessment standards

A: No deposition (staining) of lauric acid is observed on the surface of the test specimen, and there is no difference in comparison with poly(2-hydroxyethyl methacrylate) (hereinafter abbreviated as PHEMA), which has particularly excellent resistance to lipid staining among commonly used soft ocular lens materials.

B: A slight staining can be observed on the surface of a test specimen, but there is no difference compared with PHEMA.

C: soiling can be observed on the surface of a test specimen, but there is no significant difference compared with PHEMA.

D: soiling can be clearly observed on the surface of a test specimen, and there is a significant difference compared with PHEMA.

E: Significant soiling can be observed on the surface of the test specimens and there is a very clear difference compared to PHEMA.

EXAMPLES 2 TO 14

As in Example 1, various components were mixed to give the compositions shown in Table 1 and polymerized to obtain rod-shaped copolymers, which were then subjected to grinding and polishing treatment to obtain test pieces. Various physical properties of the test pieces were examined as in Example 1. The results are shown in Table 1.

The abbreviations used in Table 1 and Table 2 are explained below:

DMAA: N,N-dimethylacrylamide

SiMA: Tris(trimethylsiloxy)silylpropyl methacrylate

SiSt: Tris(trimethylsiloxy)silylstyrene

EDMA: Ethylene glycol dimethacrylate

V-65: 2,2'-Azobis(2,4-dimethylvaleronitrile)

The results of Table 1 show that the materials of Examples 1 to 14 were obtained by using a silicone macromonomer containing urethane bonds. Such macromonomers have urethane bonds not only at both ends but also optionally at intermediate positions of the silicone chain, whereby such ocular lens materials have high oxygen permeability and high mechanical strength. Furthermore, since they contain an alkyl (meth)acrylamide, they exhibit excellent transparency, water content and resistance to lipid fouling.

For the ocular lens materials of Examples 6 to 14, a silicone-containing alkyl (meth)acrylate or silicone-containing styrene derivative was further used, which further improved the mechanical strength and oxygen permeability.

COMPARISON EXAMPLE 1

A rod-shaped copolymer was prepared as in Example 1 except that 100 parts by weight of macromonomer A without N,N-dimethylacrylamide was used. Attempts were made to prepare a test piece by grinding this copolymer, but it was impossible to grind this copolymer because it was too soft.

COMPARISON EXAMPLE 2

A rod-shaped copolymer was prepared as in Example 1 except that 100 parts by weight of N,N-dimethylacrylamide without macromonomer A was used. Then it was subjected to grinding and polishing treatment to obtain test pieces. The penetration force of such a test piece was measured as in Example 1 and found to be almost 0 g. Consequently, this copolymer was found unsuitable as an ocular lens material.

COMPARISON EXAMPLE 3

A copolymer was prepared as in Example 5 except that 80 parts of macromonomer B of the following formula:

was used instead of macromonomer A. However, such a copolymer was cloudy and unsuitable as an ocular lens material.

COMPARISON EXAMPLE 4

A copolymer was prepared as in Example 3 except that 50 parts by weight of macromonomer B was used instead of macromonomer A. However, such a copolymer was turbid and not suitable as an ocular lens material.

COMPARISON EXAMPLE 5

A copolymer was prepared as in Example 1 except that 20 parts of Macromonomer B was used instead of Macromonomer A. However, such a Copolymer was turbid and not suitable as an ocular lens material.

EXAMPLES 15 TO 28

As in Example 1, various components were mixed to obtain the compositions shown in Table 2 and polymerized to obtain rod-shaped copolymers, which were then subjected to grinding and polishing treatment to obtain test pieces. Various physical properties of the obtained test pieces were examined as in Example 1. The results are shown in Table 2.

The higher the content of DMAA (Examples 15 to 28) and the higher the content of the macromonomer which is a polysiloxane macromonomer having a fluoroalkyl group (Examples 23 to 28), the greater the improvement in the resistance to lipid fouling of the obtained ocular lens material.

The macromonomer C in Table 2 is a compound of the following formula:

It is obvious from the results in Table 2 that the ocular lens materials obtained in Examples 15 to 28 have high oxygen permeability and excellent mechanical strength and water absorbency, and that they exhibit excellent transparency and resistance to lipid fouling.

The ocular lens materials obtained in Examples 23 to 28 were prepared by using a polysiloxane macromonomer having a fluoroalkyl group, and it is obvious that the resistance to lipid fouling is further improved over the materials obtained by using a polysiloxane macromonomer having no fluoroalkyl group due to the effect that fluorine atoms usually have, namely, the reduction of the critical surface tension.

The ocular lens material of this invention has the following properties.

(a) It has excellent transparency, making it suitable for use as an eyepiece lens.

(b) It has excellent oxygen permeability, and it has the effect that when it is made into a contact lens, it does not affect the metabolic functions of the cornea.

(c) It has adequate mechanical strength and relatively good rubber elasticity, and it can be processed into a lens that has excellent dimensional stability and is not brittle under various physical treatments.

(d) It exhibits significant water absorption capacity (water content of at least 5% by weight), and it is soft in the hydrated state. When made into a contact lens, it gives a comfortable feeling to the wearer, and when made into an intraocular lens, it can be folded and inserted through a small incision on the eyeball without damaging the ocular tissue.

(e) It shows low surface stickiness and has excellent resistance to lipid fouling.

(f) It is relatively hard in an anhydrous state, and in such a state it can easily undergo cutting and grinding treatment as well as precision treatment. Table 1 Table 2

Claims (10)

1. Soft ocular lens material with a water content of at least 5% by weight made of a copolymer comprising as main copolymerizable components: (A) a polysiloxane macromonomer having polymerizable groups bonded to the siloxane main chain via one or more urethane bonds, of formula (I) A¹-U¹-S¹-U²-A² (I), where A¹ is a group of formula (II) Y²¹-R³¹-(II), wherein Y²¹ is an acryloyloxy group, a methacryloyloxy group, a vinyl group or an allyl group and R³¹ is a linear or branched alkylene group having 2 to 6 carbon atoms, A² is a group of formula (III) -R³⁴-Y²² (III), wherein Y²² is an acryloyloxy group, a methacryloyloxy group, a vinyl group or an allyl group and R³⁴ is a linear or branched alkylene group having 2 to 6 carbon atoms, U¹ is a group of formula (IV) - X²¹-E²¹-X²⁵-R³²- (IV), wherein X²¹ is a covalent bond, an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms, E²¹ is -CONH- (with the proviso that in this case X²¹ is a covalent bond and E²¹ forms a urethane bond with X²⁵) or a divalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic diisocyanates (with the proviso that in this case X²¹ is an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and E²¹ together with X²¹ and X²⁵ forms a urethane bond), X²⁵ is an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and R³² is a linear or branched alkylene group having 1 to 6 carbon atoms, S¹ is a group of formula (V) wherein R²³, R²⁴, R²⁵, R²⁶, R²⁷ and R²⁹ each independently represents an alkyl group having 1 to 6 carbon atoms, a fluoroalkyl group or a phenyl group, K is an integer from 1 to 50 and L is an integer from 0 to (50-K), U² is a group of formula (VI) - R³³-X²⁶-E²²-X²²- (VI), wherein R³³ is a linear or branched alkylene group having 1 to 6 carbon atoms, X²² is a covalent bond, an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms, X²⁶ is an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and E²² is -CONH- (with the proviso that in this case X²² is a covalent bond and E²² forms a urethane bond with X²⁶) or a divalent group derived from a diisocyanate selected from the group consisting of saturated or unsaturated aliphatic, alicyclic and aromatic diisocyanates (with the proviso that in this case X²² is an oxygen atom or an alkylene glycol group having 1 to 6 carbon atoms and E²² forms a urethane bond together with X²² and X²⁶), and (B) an alkyl(meth)acrylamide, wherein the weight ratio of the polysiloxane macromonomer (A) to the alkyl(meth)acrylamide (B) is 5/95 to 90/10. 2. The ocular lens material according to claim 1, wherein the alkyl (meth)acrylamide is N,N-dimethylacrylamide. 3. The ocular lens material according to claim 1 or 2, wherein the copolymer contains a silicone-containing monomer as a further copolymerizable component, selected from the group consisting of a silicone-containing alkyl (meth)acrylate and a silicone-containing styrene derivative, in an amount of not more than 75% by weight of the total amount of the copolymerizable components. 4. The ocular lens material according to claim 3, wherein the silicone-containing monomer is a silicone-containing styrene derivative. 5. The ocular lens material according to claim 3 or 4, wherein the silicone-containing styrene derivative is tris(trimethylsiloxy)silylstyrene. 6. The ocular lens material according to claim 3, wherein the silicone-containing monomer is a silicone-containing alkyl (meth)acrylate. 7. The ocular lens material according to claim 3 or 6, wherein the silicone-containing alkyl (meth)acrylate is tris(trimethylsiloxy)silylpropyl (meth)acrylate. 8. The ocular lens material according to any one of claims 1 or 7, wherein the water content is 10 to 60% by weight. 9. A process for producing a soft ocular lens by cutting and grinding a copolymer according to any one of claims 1 to 8 in an anhydrous state and then equilibrating hydration to a water content of at least 5% by weight. 10. Use of an ocular lens material according to one of claims 1 to 8 in a contact lens, an intraocular lens or an artificial cornea.